This proposal is being submitted for the Behavioral Science Track Award For Rapid Transition to study the potential neurobehavioral effects of prenatal exposure to tricyclic and serotonin selective reuptake inhibitor (SSRI) antidepressants. Lack of this information frequently limits the treatment of mood disorders in women Aims: The proposed naturalistic study will assess the potential effects of timing of prenatal exposure to drug, dose of drug used, changes in dosage, and timing of last dose prior to delivery on infant behavior. The incidence of a potential antidepressant withdrawal syndrome in infants following exposure to antidepressants and whether this syndrome is transient. will be determined. Behavioral differences that may be observed in exposed and non-exposed infants will be described. The contribution of factors such as chronicity of maternal illness, severity of illness and other psychosocial stressors to the infant's behavior will be evaluated. Design: The study will compare twenty mother infant dyads with prenatal antidepressant exposure to twenty dyads with a pregravid history of major depressive disorder (MDD) but no drug exposure and twenty control dyads. Method: Data from mothers collected antenatally and twice in the first month of infant life will include the structured clinical interview for DSM!V. (SCID), the Overall Clinical Global Impression Scale (CGI), the Hamilton Depression Scale' the MDD Schedule of Affective Disorder Symptoms, the Kennerley Blues Questionnaire (daily for 28 days) and the self reported Beck Depression Inventory, Social Adjustment Scale (SAS) and the Dyadic Adjustment Scale (DAS). Prenatal and postpartum pharmacologic and psychotherapeutic treatments will be described. Infant behavior will be assessed at 3-6 and 28-31 days using the Brazleton Neonatal Behavioral Assessment scale. Information will also be obtained from the obstetric and pediatric record.